Cellulosic fibrous materials



United States Patent Oflice 3,503,793 Patented Mar. 31, 1970 3,503,793CELLULOSIC FIBROUS MATERIALS Hans Brandeis, Limburgerhof, Pfalz, KlausPfleger, Ludwigshafen (Rhine), and Heinz Bille, Limburgerhof, Pfalz,Germany, assignors to Badische Anilin- & Soda- FabrikAktiengesellschaft, Ludwigshafen (Rhine), Ger- US. Cl. 117-136 3 ClaimsABSTRACT OF THE DISCLOSURE Fireproofing cellulosic fibrous material withcompounds having the formulae CH2 l in which m denotes a value from 2.7to 1.0 and n denotes a value from 1.8 to 1.0, and cellulosic materialfireproofed therewith.

and

OHzCl The present invention relates to a process for the fireproofing ofcellulosic fibrous material using certain phosphorus amides andchloromethyl phosphonarnides and to the cellulosic material finished inthis way.

The amides, particularly the dialkylamides and the 1,2- alkylenamides ofphosphoric acid and of alkylphosphonic acids and haloalkylphosphonicacids, are generally known as fireproofing agents for cellulosic fibrousmaterial.

It is possible by means of these agents, which are in general fixed tothe fibrous material by heating, to diminish the flammability of thefibrous material considerably, but usually only with impairment of otherdesirable properties. For example, this treatment may produce,embrittlement, a tendency to yellow of textiles finished in this way,and low resistance to washing of some of these prior art fireproofingfinishes. This is especially true of the compounds giving thefireproofing effects which have hitherto been the best and mostresistant to washing, namely tris-N-aziridinylphosphine oxide(phosphoric acid trisethylenamide, APO) and chloromethylphosphonicbisethylenamide (APCl) which have the formulae:

CHzCl which moreover are very toxic in the unchanged, i.e. unfixed,condition. When using other phosphoric amides and phosphonic amides(including the nontoxic compounds phosphoric-tris-methylarnide andchloromethylphosphonic-bis-methylamide) good fireproofing effects areobtained but they are not resistant to washing.

The object of the present invention is to provide new fireproofingagents for cellulosic fibrous materials which give optimum andwash-resistant fireproofing effects with a minimum of deleterioussecondary effects.

We have found that cellulosic fibrous materials can be given awash-resistant fireproof finish by means of phosphoric amides ofchloromethylphosphonic amides with excellent success by applying to thefibrous material a composition containing or consisting of a mixture ofcompounds (I) and (II) defined by the following general formulae:

in which m may have any value from 2.7 to 1.0 and n may have any valuefrom 1.8 to 1.0, these indices corresponding to the average frequency ofthe methylamido groups and ethylenamido groups in weighable amounts ofthe trivalent compounds (I) or the divalent compound (II). Thus thecompounds (I) and (II) are themselves mixtures. Mixtures of (I) and (1))may also be used.

The mixtures of compounds (I) and (II), which are referred tohereinafter as compounds for simplicity, are obtainable by conventionalmethods, preferably by reaction of 1 mole each of phosphorus oxychlorideor chloromethyl-phosphonyl dichloride with m or n moles of methylamineand 3-m or 2-n moles of ethylenimine in an inert organic solution attemperatures of from about -40 C. to +40 C. It is recommended that thesolvent (for example methylene chloride, benzene, dioxane,tetrahydrofuran of ether) be placed in a reactor and the reactants bepassed into the same simultaneously at the same rate in proportion tothe molar composition of the product. An appropriate molar excess ofmethylamine, ammonia or a tertiary amine should be used to bind hydrogenchloride liberated in the reaction. Both methylammonium chloride and thehydrochlorides of tertiary amines and also ammonium chloride areinsoluble in the said solvents and can be filtered off therefrom. Thesolution is then evaporated, advantageously at subatmospheric pressure,after which the product remains as a colorless syrupy liquid. So that itshould remain stable for long periods it is advisable to dilute it, forexample with water, dioxane or dimethylformamide. Compounds (I) and (II)are obtained in which the indices in and n denote only the averageamounts. The mixtures of molecules formed actually have statisticaldistribution of the amine radicals on the phosphorus.

By applying to the fibrous material we mean using the flame-proofingmixture by a conventional method or any method which is known in theart.

The new agents are advantageously used in 5 to 50% aqueous solution(percentages here and hereinafter being by weight) for finishingcellulosic fibrous materials, the amount being such that the fibrousmaterial absorbs from about 5 to 50%, preferably from 10 to 30%, of thedry weight of (I) or (II) depending on the desired intensity of thefireproofing effect. When mixtures of (I) and (II) are used, the saidpercentages relate to the total weight of (I) and (II). Application maybe for example by dipping, spraying or padding. After the impregnatedfibrous material has been dried, the agent is fixed thereon by heatingfor from about two to twenty minutes at about to 200 (1., preferablyfrom to C. Following this, the fibrous material thus finished is given aconventional after-treatment for removal of unfixed agent; for exampleit may be washed with hot dilute aqueous alkali metal hydroxide solutionor alkali metal carbonate solution.

The agents (I) and (II) which, as already stated, may be used together,are compatible with all other agents for textile finishing, particularlywith a great variety of aminoplast-forming monomeric, oligomeric andpolymeric compounds and may be used together with them. In otherrespects, the method according to this invention may be carried out byall procedures and in all apparatus which would otherwise be used forfinishing fibrous materials.

Cellulosic fibrous materials may include cotton, linen, sisal, hemp,regenerated cellulose and wood-wool in the form of filaments, threads,fibers, wadding, nonwoven fabrics or sheet materials, such as textilesand papers of all types. These materials may be mixed with others, foexample wool, silk, polyester, polyamide or polyacrylonitrile, the totalfireproofing eifect then corresponding to that of the cellulosefraction.

The invention is further illustrated by the following examples.

EXAMPLE 1 A cotton cloth is impregnated with a 30% aqueous solution of acompound (I characterized by m=2 so that the amount of finishing agentfixed to the cloth at 160 to 170 C. is about 22% of the dry weight ofthe cloth. Values for the fireproofing and resistance to washing of thefinish (determined according to German standard specification DIN53,906) are given in Table 1. DIN is the abbreviation for DeutscheIndustrie Norm, a German industrial standard. DIN 53906 is equivalent toASTM-D-1230. DIN 54011 is equivalent to ISO-R105. The followingabbreviations are used in the table:

Q=amount of compound fixed on the fiber Q =amount remaining on the fiberafter washing three times with sodium carbonate solution at the boil inaccordance with DIN 54,011

B=burning time in seconds T=tear length in centimeters.

TAB LE 1 Finished with I (m=2), percent Not finished EXAMPLE 2 Twopieces of cotton cloth are impregnated respectively with a 23% and 30%aqueous solution of a compound (1 characterized by m=1.8 so that theamount of finishing agent fixed on the cloth at 150 to 170 C. is about15% and about 20%, respectively, of the dry weight of the cloth. Valuesfor fireproofing and resistance to washing of the finish, determinedaccording to DIN 53,906, are given in Table 2 using the sameabbreviations as in Table 1.

TABLE 2 Finished Finished with I with I (m=1.8), (m=1.8). Not finished Ipercent Not finished percent 15 20 8. 13. 16 B Burns through 0 Burnsthrough... 0 T do 11. 0 ..do 10. 0

These elfects are as good as when using the much more toxic APO(m=zero).

The compound (I is prepared as described in Example 1, like the compound(I 4 EXAMPLE 3 A cotton cloth (two pieces) is impregnated with a 23% anda 30% aqueous solution of a compound (I characterized by m=1.5 so thatthe amount of the finishing agent fixed on-the. fabric at 16 0 to 170 C.is about 15 and about 18% of the dry weight of the'cloth, respectively.

Values for fireproofing and resistance to washing of the finishdetermined according to DIN 53,906 are given in These eifects are asgood as when using the much more toxic APO (m=zero).

The compound (1 is prepared like the compound (I according to Example 1.

EXAMPLE 4 A cotton cloth is impregnated with a 25% aqueous solution of acompound (I1 characterized by n=1 so that the amount of finishing agentfixed on the cloth at to C. is about 18% of the dry weight of the cloth.

Values determined according to DIN 53,906 for fireproofing andresistance to washing of the finish are given in Table 4, by referencetothe extent of carbonization in centimeters. The following abbreviationsare used in Table 4:

T=tear length in cm without washing 7 T =tear length in cm after washingwith water at 60 C. lT =tear length after a single wash at the boil withsoap and soda 3T =tear length after washing three times at the boil withsoap and soda.

TABLE 4 Extent of carbonization (em.)

Without; finishing Finished with 11 '1 More than 30 7 Tw 8 1TH. 9 3T.,.11

These effects are as good as when the much more toxic APCI (n =zero) isused.

The compound (IP) is prepared like the compound (1 as described inExample 1, substituting chloromethylphosphonyldichloride for phosphorusoxychloride.

EXAMPLE 5 length in cm after three washes at the boil according to DIN54,011:

TABLE 5 Without any finish: Burns Through Sample A 11 Sample B Theseeffects are as good as when the much more toxic APCl (n=zero) is used.

The compound (I1 is prepared like the compound (I as described inExample 1, substituting chloromethylphosphonyldichloride for phosphorusoxychloride.

Welclaim:

1. Fireproofed fibrous material consisting of or containing cellulosewhich has been finished with 10-30% by weight, with reference to thecellulose, of a mixture of compounds having one or both of the FormulaeI and II:

(NH-CH3); (NH"-OH3)n O=P P /CH;:] P /OHz:I

N I or N l \CH2 z-m H2 2-n groups and ethylenamido groups in weighableamounts of said compounds.

2. Fireproof fibrous material as claimed in claim 1, wherein saidcompounds consist essentially of compounds having the Formula I.

3. Fireproof fibrous material as claimed in claim 1, wherein saidcompounds consist essentially of compounds having the Formula II.

References Cited UNITED STATES PATENTS 2,891,877 6/1959 Chance etal117136 3,205,034 9/1965 Chance 117--136X FOREIGN PATENTS 892,131 3/1962Great Britain.

WILLIAM D. MARTIN, Primary Examiner H. J. GWINNELL, Assistant ExaminerU.S. Cl. X.R. 117-143; 2528.1

232 3; UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,5 3,793 Dated Mgroh '51. 1970 Inv Hans Brandeis et a1 It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 2, line 18, "(1))" should read --(II)--.

Column 5, claim 1, formula I, that portion of the formula reading "CHshould read H SIGNED ANu SEALED L 2 1970 (SEAL) Attest:

' mums r. sonurm. M. Fletcher, In c missione'r of Paten AttestingOfficer

